Several aspects of genetic and immunologic control of immunoglobulin and complement production are being studied. The relationship of the mouse H-2 complex to functional levels of C1, C4 and C2 and the Ss protein are being investigated. All have been found to be under control of S region genes and the mechanism of that control is being elucidated. A system whereby production of the fifth component of complement can be suppressed by neonatal administration of anti C5 antibody has been developed. Optimal conditions, genetic control and the mechanisms of suppression are presently being studied. BIBLIOGRAPHIC REFERENCE: Goldman, M.B. and Goldman, J.N. (1976) Relationship of Functional Levels of Early Components of Complement to the H-2 Complex of Mice. J. Immunol. 117: 1584-88.